The outspoken Sandberg tells women that they need to “lean in” at work and assert themselves more. Hit the accelerator, so to speak.

Relevant Advice for Women Over 50

Overall, I find her advice to be relevant for women in all stages of their careers, including those of us in our 50s and beyond, which I’ll explain in a bit.

She concedes that “critics will point out that it is much easier for me to lean in, since my financial resources allow me to afford any help I need,” referring to paying for nannies and the like. But, she adds, “my intention is to offer advice that would have been helpful to me long before I heard of Google or Facebook.”

Her basic message: “More female leadership will lead to fairer treatment for all women,” she says.

Even with a message that sounds totally sensible, Sandberg has hit a tender spot, especially when it comes to the issue of combining work and family.

Critics Have Been Harsh

Commentators writing in places like The New York Times, The Washington Post and the blogosphere have launched into her “feminist” audacity and slapped Sandberg down for a wide range of misdeeds and elitism.

I, too, initially felt a knee-jerk need to criticize Sandberg. She is smart, rich and successful. But I stopped myself.

I read her book, then watched and listened to her interviews on 60 Minutes, Good Morning America and NPR. (She also appears in the PBS documentary, Makers: Women Who Made America.)

Both in Lean In and her media appearances, I think Sandberg comes off as genuine and passionate, someone who has taken a risk to speak out concerning a problem she cares deeply about … because she can.

Sandberg spends the lion’s share of her book on the challenges facing working women with young children. But the plight of women without kids in the workplace is virtually ignored, even though nearly 1 in 5 American women exits her childbearing years childless.

But since many of my friends and I have experienced quite a few of the career woes and setbacks that Sandberg discusses, I want to tell you about five steps Sandberg recommends and I endorse:

1. Be more open to taking career risks. Women tend to avoid stretch assignments and new challenges on the job, Sandberg says. They worry too much about whether they have the skills needed to take on a new, loftier role.

When offered an opportunity, they fall back on the excuse that they're unfamiliar with that kind of work or it isn't what they went to school for.

“At a certain point, it’s your ability to learn quickly and contribute quickly that matters,” Sandberg writes. “Women need to shift from thinking ‘I’m not ready to do that’ to thinking ‘I want to do that — and I’ll learn by doing it.’”

As More magazine editor-in-chief Lesley Jane Seymour wrote in her blog post on Lean In, Sandberg is recommending women “grab for leadership roles even if we are only 60 percent certain we have the credentials for that step — because, after all, that is what men do.”

2. Skip the people pleasing. Sandberg confesses that during her first formal review at Facebook, chief executive Mark Zuckerberg told her that her "desire to be liked by everyone" would hold her back.

When I asked one of my working mom friends who lives in a small South Carolina town what she learned from Lean In, she said: “It comes down to stepping up and being willing to lead, getting some confidence, pushing back on things, challenging others' decisions.”

3. Visualize your career as a jungle gym, not a ladder. This is my favorite of Sandberg’s tips.(Maybe that's because when I was growing up I loved playing on the jungle gym in our backyard.)

She attributes the analogy toFortune editor-at-large Patricia Sellers, who heads up the magazine’s Most Powerful Women franchise.

To me, it’s a great image of the 21st-century career path. “Ladders are limiting,” Sandberg writes. “Jungle gyms offer more creative exploration. There are many ways to get to the top of a jungle gym. The ability to forge a unique path with occasional dips, detours and even dead ends presents a better chance for fulfillment.”

4. Allow yourself to fantasize about your career. “I believe everyone should have a long-term dream,” Sandberg writes. She also believes you should have an 18-month plan to pursue immediate workplace goals, like learning new skills.

In essence, Sandberg is saying, you need to constantly ask yourself, "What can I do to improve myself at work?"

“If I am afraid to do something,” she says, “it is usually because I am not good at it.”

5. Start a Lean-In circle. This is a peer group of eight to 10 women who meet monthly, offering one another encouragement and development ideas. Her Lean In website offersdownloadable circle kits that show you how to form and run one. There’s also a growing Lean In community, where women share their stories online through Sandberg's site.

When I asked one of my pals about the concept, she told me: “I have had this conversation with many of my professional friends and I would actually love to start a Lean In circle. But then I get the same response from everyone, ‘I would love to, but who has the time?’”

But, as another friend said, "Isn't that really what the problem is to begin with?"

She’s right.

Kerry Hannon has spent more than 25 years covering personal finance for Forbes, Money, U.S. News & World Report and USA Today. Her website is kerryhannon.com. Follow her on Twitter @kerryhannon.

I am a national keynote speaker, best-selling author and columnist. My expertise: personal finance, career transition, and retirement. My latest books are Great Jobs for Everyone 50+, Money Confidence, Getting The Job You Want After 50, Love Your Job: The New Rules of Career...